Project 3.2: Exoplanet atmospheres at high spectral resolution
Project 3.2 is led by Christophe Lovis. This project focuses on the observational study of exoplanet atmospheres by means of ground-based high-resolution spectroscopy. The goal is to probe the chemical composition and atmospheric structure of a variety of objects, ranging from hot Jupiters to temperate Earth-like planets. High-resolution spectroscopy circumvents the practical difficulties caused by Earth’s atmosphere and rivals space-based spectrophotometry in terms of exoplanet characterisation potential. It reveals the physical properties of atmospheres by resolving spectral line profiles, which constrain chemical abundances, temperature profiles, global circulation patterns, and planet spin rate. Two main approaches will be pursued in this project: transmission spectroscopy of transiting exoplanets and spatially-resolved spectroscopy of very nearby (non-transiting) exoplanets using extreme adaptive optics (AO).
High-resolution transmission spectrum of the warm Neptune HAT-P-11b obtained with CARMENES around the near-infrared metastable helium triplet. Absorption by the planet continuum has been removed. A significant excess absorption from an extended upper atmosphere of helium is detected at 21 sigma. The transmission spectrum (in black) is plotted in the planet rest frame, and is averaged over two independent epochs (in blue and orange). Our best fit model is in red.
Bourrier, V.; Lecavelier des Etangs, A.; Ehrenreich, D.; Sanz-Forcada, J.; Allart, R.; Ballester, G. E.; Buchhave, L. A.; Cohen, O.; Deming, D.; Evans, T. M.; García Muñoz, A.; Henry, G. W.; Kataria, T.; Lavvas, P.; Lewis, N.; López-Morales, M.; Marley, M.; Sing, D. K.; Wakeford, H. R.
Astronomy & Astrophysics, Volume 620, id.A147, 14 pp.
Mansfield, Megan; Bean, Jacob L.; Oklopčić, Antonija; Kreidberg, Laura; Désert, Jean-Michel; Kempton, Eliza M. -R.; Line, Michael R.; Fortney, Jonathan J.; Henry, Gregory W.; Mallonn, Matthias; Stevenson, Kevin B.; Dragomir, Diana; Allart, Romain; Bourrier, Vincent
The Astrophysical Journal Letters, Volume 868, Issue 2, article id. L34, 6 pp. (2018).
Hoeijmakers, H. J.; Ehrenreich, D.; Kitzmann, D.; Allart, R.; Grimm, S. L.; Seidel, J. V.; Wyttenbach, A.; Pino, L.; Nielsen, L. D.; Fisher, C.; Rimmer, P. B.; Bourrier, V.; Cegla, H. M.; Lavie, B.; Lovis, C.; Patzer, A. B. C.; Stock, J. W.; Pepe, F. A.; Heng, Kevin
Astronomy & Astrophysics, Volume 627, id.A165, 26 pp.